Heretofore, as a container containing a medicament, there has widely been used a container using a single-layered film formed of a linear polyolefin or a multilayered film comprising a linear polyolefin layer and a polymer layer having barrier properties against moisture or a gas. Also, the use of a multilayered film comprising these films bonded to each other using an adhesive has recently been approved by revision of the Pharmacopoeia in Japan and a medical container provided with various performances has been developed, and thus it becomes possible to contain various medicaments in such a container.
However, since it has become possible to contain various medicaments as a result of the improvement in the performances of the container, there may arise problems such as decrease in the content of an active ingredient of a medicament due to an interaction between a low molecular weight component eluted into the container from the linear polyolefin layer and/or the adhesive layer, increase in the content of related substances, increase in the content of insoluble fine particles in a liquid medicament and the like.
Under these circumstances, there is an apprehension that any adverse influence is exerted on the medicament to be packed. To dispel such an apprehension, there has been proposed, as a polyolefin packing material which is less likely to be adversely influence, a polyolefin packing material for packing a medicament, which contains 150 ppm or less of a substance having 12 or more and 26 or less carbon atoms, and is obtained by treating a linear low-density polyethylene resin at a resin temperature of 170 to 230° C. under reduced pressure of 10 Torr or less using a Vent-type extruder (see Japanese Patent No. 2,826,643 which is referred to below). Also, as a packing material for foods, beverages or drugs, which is less likely to cause elution of a low molecular weight substance, there hwe been proposed a low elution packing material obtained by laminating a sealant layer (for example, a linear low-density polyethylene or non-stretched polypropylene film) on a base material via a cyclic olefin copolymer layer or a blend polymer layer formed of a cyclic olefin copolymer and a polyolefin resin (see Japanese Unexamined Patent Publication (Kokai) No. 2001-162724 which is referred to below)[0005]
However, a medical container using these packing materials has a problem in that when a drug is a solid medicament (for example, a powdered medicament) which is mixed with a dissolving liquid to prepare a liquid medicament upon use, insoluble fine particles in the liquid medicament increase. Also, it is required for such a medical container to have suitability as to radiation exposure upon irradiation sterilization, in addition to the suitability as to high temperature sterilization such as high pressure steam sterilization, hot water sterilization or the like.    Patent Reference 1: Japanese Patent No. 2,826,643    Patent Reference 1: Japanese Unexamined Patent Publication (Kokai) No. 2001-162724